Air charger for hydropneumatic systems



May 23, 1950 A. w. BURKS AIR CHARGER FOR HYDROPNEUMATIC. SYSTEMS 2 Sheets-Sheet 1 Filed March 9, 1945 lv II,

May 23, 1950 A. w. BURKS 2,509,130

AIR CHARGER FOR HYDROPNEUMATIC SYSTEMS Filed March 9, 1945 2 Sheets-Sheet 2 'E LZ.

by WX ak/m gig/5 Patented May 23, 1950 CHARGEE Q mRQPNEUMATIC SYSTEMS Arthur W; Burks, Decatur; 1-11., assignor to' Decatur Pump Company, Decatur, I1l a. oorporation of Illinois ApplicationMarch 9, 1945 Serial NQl 5.8,1,,8.29.

Claims. (Cl. 1-03-fi)- This invention relates to an air charger for h r -pne ma sy m andme p rt cularly t n, air ha g r f r supp ying air to a hydropneumatic tank in response to the pneumatic p ssur requirements of th syst m- The present. inventionrelates to. a novel and i roved air ch rger mecha ism r main in ing the pneumatic pressures in a .hYdro-pnem matic supply n within t e desired limits- T ai r er of y nve o perates to su ply a r to. the hydrorpneumatic tank if required whene e e p p h sup l esthehydrc-pneuir at c tank withwater is operated,

An po n ture of. my inv ntion the prov sion-o a ediieter. o aspira or, onera e hr a fiow o wat u der p essure from he pump when the air cushion in the tank requires replenieh ng, d aw a mosph ic air. into theair ha teer casing for subsequent displacement into the hydro-pneumatic tank to replace losse of .air fr m the a an build up the air pre s re therein to Within the desired limits. A float valve cooperates with theeductor, or aspirator, toelimiha e r at le s du e, the p i lity of air drawn in hy e du er fi ding tsway nto. the

p p and ausin h pump to become air oundlevel, to introducea charge of air into the tank.

Ij noair is required in thehydro-pneumatic tank,

no new charge of air is delivered into the tank,

but air is mere y t drawn fr m he tank and expelled back thereinto. The device is thus fully au omatic a d requ es. 1i l if any, attentio It is her h i portant ob ect o is. invention to preyid an automati a l qp rat a h r for maintaini h e ir pne mati pressure within a hydro-pneumatic, tank of a water supply system, the air charger being responsive to the pumping operation when the level of the water in the tank is'a bove normal-taintroduce a charge of air into the hydro pneuma tic tank. The air charger includes an eductonor aspirator, for aspirating air into the system and a float controlled valve on the suction side ofthe pump for eliminating or reducing the possibility of such air being drawn into thelpump to thereby lessen its efficiency.

It isa f rther impo tan objector-thi n ention to p ovide an ai c rg r theonereti n o wh ch depends'upon the action of an eductor, or aspirator, actuated by the pressure discharge of water fromt-he pump, in combination with a float controlled valve on the suction sideqi the pump to reduce the possibility of air getting bach into the suction line and destroying the prime of the name- It is astill further important object of this invention toprovide an air ehargerwhich, in addition to its function of maintaining the desired pneumatic pressure in a hydro-pneumatic tank, is so arranged and positioned asto serve as a primer for the pump Supplying the hydro-pneumatic tank. 4

other nd further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawin O th draw n s:

Figure 1 is a fragmentary vertical sectional vi wl art r. in el io o r h r m- Vbed insi h princ p s f m n e t on- Fi ure 2 is. a iragmentary broken sectional view-pa tly in e evat on of a modi e m f. my air charger.

he hown. on e d aw s:

In F u -li he. r er n nume al 70 ind tes g nera y a. hyd o-pne m ic t n w h, as is c st m i part ally fill wi h a er maint n er thenr ssur o n ir shi bov the Water ev l- Weterissuppl h h r ,nneumatic tan I! y apumn U, prefera ly of t e een rii ieal ype ..wh e is, c nne ed th ou a suction intake 12 to a water supplypipe l3, ZSaid supply pipe [3 has a foot valve [4- at its lower end, which, when installed, ,extendsinto the source of water that supplies the pump H.

Thepump II is connected at its discharge end the nipple H3, or in the opposite directioninto the chamber 45 of the'air' charger 2!). Within the fitting l--lthere is positioned an eductor, or

, aspirator, 2 I, through which water from the pump mg throughthe eductor.

For this purpose, thefi-tting I1" is provided with an apertured side connection 24 that is threaded at its outer end for receiving the air valve 23. Said air valve 23 includes a plug 25 having a small diameter bore 26 extending therethrough, terminating at its inner end in a counterbore for receiving a resilient seat 45. A ball valve 21 normally seats upon said seat 45. Said valve has a stem 28 passing .through said bore 25 and terminating in an enlarged head 29 that projects beyond the plug 25. Thus, when there is a pressure flow of water through the eductor 2|, the reduction in pressure that takes place at the throat 22 causes the ball valve 21 to rise off its seat 45 and open the bore 26 to admit air into the throat 22 for admixture there with the water passing therethrough. The mixture of water and air is discharged from the eductor into the chamber 45. 1

Said air charger is connected at its upper end through a nipple 41 and a coupling 34 to a conduit 3|. The upper end of said conduit 3| is connected through a check valve fitting 32 to the tank ID at about its normal water level, as indicated by the dot-dash line N. Said fitting 32 is provided with an enlarged bore 33 opening at its inner end into the tank In and at its outer end merging into a reduced bore 34. A conical ball seat 35 is formed between said enlarged and reduced bores 33 and 34, respectively, and a ball 36 is positioned in said enlarged bore 33 for the purpose of seating against said conical seat 35 and closing ofl the reduced bore 34 under certain conditions. A stop pin 31 prevents the ball 35 from becoming displaced entirely from the bore 33.

This arrangement of the ball valve fitting 32 is such as to permit the flow of air through the fitting in either direction but prevent the flow of water from the tank through the fitting into the conduit 3|. The latter is prevented by reason of the fact that the ball 36 in response to a flow of water from the tank into the fitting 32 rises against and seats upon the seat 35, thus closing off the reduced bore 34.

The air charger 20 is provided with a lower passaged cylindrical boss 35 which is in alignment with the upper nipple 41, and which is internally threaded to receive the threaded end 39 of a continuation of the vertical intake pipe I3. An annular valve seat 40 is positioned in a counterbore formed at the inner end of the passage through the boss '38. A float controlled valve 4| having a float 42 mounted on its upwardly extendin stem 43 serves to control the port defined by the annular seat 40. The upper end of said stem 43 extends freely into the passage through the nipple 41, the walls of which serve as a guide therefore.

The operation of the air charger will now be described. When the pump is not running, the pressure equalizes itself throughout the system. Since the air charger is below the level of the water in the tank It, the chamber 45 fills con pletely with water. The float 42, accordingly, holds the valve 4| off its seat 40. The foot valve |4, prior to starting up the pump II, is closed.

When the pump l is started, the water already in it and in the chamber 45 serves to prime the pump. The suction created by the pump causes the foot valve H to open and let water be drawn up through the intake pipe l3. The pump discharges this water under pressure through the pipe i6 into the fitting At the fitting H the flow of water from the pump divides, part of the water passing into the tank and the other part of the water passing through the eductor 2|. The passage of water under pressure through the eductor 2| causes a reduction of pressure at the throat 22, resulting in the air valve 2'! being lifted off its seat and air being drawn into the eductor for discharge in admixture with water into the chamber 45. There, the water and air separate .by gravity and the air accumulates above the Water level, which may be indicated at this point by the dotted line W.

This action continues until the accumulation of air in the float chamber of the air charger 25 causes a drop in the water level to the point at which the float is depressed sufficiently to seat the valve 4| upon its seat 43. The diflerence in pressure within the float chamber and the suction line l3 holds the float valve 4| seated. Water, however, continues to pass through the eductor 2| until the pressure within the float chamber 45 becomes equal to the pressure within the tank Id, at which point the flow of water through the jet ceases and the air contained in the float chamber 45, being below the water level in the tank, is displaced therefrom because of its difference in density and is caused to pass through the conduit 3| and the check valve fitting 32 into the tank It.

During this period and so long thereafter as the pump continues to operate, the float valve 4| remains seated due to the diiierence in pressure between the suction line and the float chamber. As soon as the pump ceases to operate, however, the pressure on the system becomes equalized and the buoyancy of the float 42 operates to open the valve 4| and establish communication to the suction line IS.

The foregoing description of the operation applies whenever the level of the water in the tank H) is at Dr above the normal water level indicated by the dot-dash line N, as for instance at the level indicated by the dot-dash line H.

If, however, the water in the tank I0 is below the normal water level, as, for instance at the level indicated by the dot-dash line L, the ball check 36 remains unseated and permits air to be drawn into the conduit 3| and thence into the float chamber 45. Under these conditions, there will be no difference in pressure between that in the float chamber and that within the tank H), with the result that the eductor 2| will not operate to draw in air through the air intake 23, but, instead, will draw air in from the tank l0 through the check valve fitting 32 and the conduit 3|. Such air displaces water from the chamber 45 into the suction line l3 until the level within the float chamber is sufficiently lowered that the float 42 operates to seat the valve 4|.

Since the mixture of air and water coming from the eductor 2| when atmospheric air is being drawn in through the air intake 23 is of an intimate nature, the float chamber 45 should be sufficiently large to allow the air to be released from the water before any water is drawn from said float chamber into the suction line |3 to the pump. Otherwise, the pump might draw in suflicient air to cause it to lose its prime.

In the modified form of my air charger illustrated in Figure 2, a hydro-pneumatic tank, indicated by the reference numeral 53, is supplied with water, as previously described, by a centrifugal pump 5| having an intake pipe 52 leading through a foot valve 53 and a strainer 49 to a water supply pipe 54. Said pump 5| may be directly connected to the bottom of the tank 5|! through a discharge pipe 55.

air charger, indicated-generally by the reference 'numeral -EG is cc'mnected by-- piping- 51 tothe pumpdischarge pipe 55-through afittting 58", which is incontrolled communication-through a port 59- with the intake side of the pump above the foot valve 53.- Saidaircharger 56' is also connectedat its top by means of a'pipe-GO- through acheckvalve fitting '6 I -to-t-he-tank- 50wator' about its" normalwaterlevel; as indicated by the dotdashlineN. The checkvalve fittingli issimilar. in all respects tothefitting -32 of Figure -1 "and performs the same-function as-described tor-that fitting.

The air-chargerifi provides a float-chamber 62 in which is positioned a float 6-3 havinga valve 6* attached" thereto by a; stenr'65 for ccntrollin-g; the'port 59; Saidstem=65 -passes freely through an aperturedplug GB in'the upperwall fibot-said fitting-5&1 The aperturedplug Gtprovideaaguide forthevalve 65;

Theair charger 56 -'isfurther-provided wither-1 offsetupperchamber; in the lower wall of which is 'positionedan airintake valve 68=similar ilraill respects: to the air intakevalve 23'previously described.

- The fitting tit-house's aneductor l having an intake nozzle 1 I --1'orreceiving* water underpressure through the pipingi-l and a dischargenozzle 12 opening into the interior- 13 of said fitting. The" eductor'ill- "is" provided with-an apertured throat 1 i which isin communication with'the float chamber 62 through a passage in the upperwallof-saidfltting.

' The "operation of theair charger-illustrated in Flgure2 wilinovrbe explained.

When the pump 5l is started, assuming the water level in-thetanlr 50=-to be-at orabove the normal water --le-ver- N, for instance at the level indicated-by the-referencecharacter H, the ball check fitting M prevents the flow of water through the piping-8'0 into the aircharger 56. The float chamber 62- is however, "filled with water from the end ofthe previous cycle. Accordingly; the float-63 holds-the valve 64 off of its seat 59 to" permit thewater in thefloat cha'mber M te serveas a prime-for the pump il Assoon as the pumpastartspumping, it creates a-sufiici'ent suction inrthe intake 5-2 tocpen the f-cotvalve 53 and draw lnwater through the in take supply pipe '54. Thew-aterdischarg'ed fr0mthe pump--5l -throughthe discharge pipe 55 flows partly into the tank 50 and partly through the piping 51 into; the eductor 1-0. The reduced pressure at the throat of said eductor causes water-to be drawn from the-float chamber 62 through" theopening thusljoweringthe water level within the float chamber-62 and effecting -a reduction in the pressure above'the water. Such reduction in pressurecauses the air intake valve 89 happen and air to be drawn into the ofiset chamber '68.

When the water level-in the float chamber 62 has dropped sufli'cientlyto-allowthe float control valve 64 to closethe port '59, the continued flow ofwater through theeductor 10- now flows out through thethroat aperture M; through the'opening '15 and into thefloat chamber 62. The continued flow of-"water into the float chamber 62 effects the displacement-of the air therefrom into the tank Elllthroughthe pipingfill-and ball check valve fitting 6|; 'Thefloat-valvefl remains 'seated'because of the -difference in pr'essure between that in the flow chamber 62 and that-in the pump intakeplping '52 Water-continues to flowrrrcm the throat ofthe eductonintothe cham- 6.. leer- G2 until pressures'arebalanced within thefloat ohamber fl and the -tar1le'5l); after ---whichfiow throughthe eductorceasesn Assoon asthe -pump stops, the --foot valve 53 closes and pressure-is -equalized betweenthetarik and suction -side-ofi the pump through the pump itself; thereby permitting the float =63 again to rise and open the port--59.- Thec hargeristhen ready--to-repeat the cycle-When the pump again starts: up.

r i If; however, the-water levelvin -the tank is below the normal water-level, as for instance at the levelindieated by t'he dot-dash line L, aira is preferentially d-rawn through the check valve fitting -6-l and the =piping= -intothe float valve 6 2; and no atmospheric air ise taken in through the =-a-ir'-= intake valve'tm rhe air so. takeninto the-floatohamberti is displaced ba-ole into the tank fill; as previouslydescribed, the pump Stops.

'I-husonly whenthe pressure demand or the hydro-pneumatic --tank- 50" requires. it isatmospheric air: introduced-into-the -tank through the air'intakevalveassembly 68.

In both :of the forms otconstruction illustrated in Figures and -Z the-broad principle isthe same, namely, theusebf an eductor or drawing inatmosphericair-when-=the level oi' -thewate-r isat or above v the normal level in the hydro-pneumatic-tank; and the-use of the -fioat valve f or controlling the flow of water from the air chargerto the intak -side of the-pump'so "that the eductor can operate'when the 1 pump isoperating to draw a-fu-ll charge of-air into the charger and subse quentlyefiect the displacement of such air into the hydro-pneumatic tank. Also, in both-modificationsof my invention, the air charger serves thedual functionof a primer for the pump because of its beingpositioned above the intake of the pump and because of the arrangement whereby pressures equalize"themselves within the air chargerjiandwithin"thehydro pneumatic tank and the air charger'fills up with *waterupon the pump being stopped;

' "It will; ofcourse; be understoodtlratvarious'details-of" constructiommay "be varied'through a wide range"withcutdepartingfrom the principles of this invention and it is, therefore, not. the purpose to. limit the patent granted hereon otherwise than necessitated 'by the scope of. the ap-- pendedclaims;

I claim as my'invention:

11. In a. hydro-pneumatic. system including a hydro-pneumatic tank and apump for supplyingwater to thetanl; through a discharge line, an air charger for supplying air to.v the tank in accordance. with he l v l of wa er therein, as main ained. by the pu p, said charg r c pr sng' a asing having an opening for valveecontrolled connectionto'thetank at about the normal water levelthereinto permit air fiow through the, opening in either direction and water flow therethrough only in: the direction of the tank, said casing 'ha-ving a 'fluidrflow op'ening for connection tothe' suction side of the pump, a valvecontrolled" air intakefor admitting atmospheric air 'intosaid casing; anaspiratorior connection to 'the pump, discharge line and-having a constricted' throatportion' vented to cooperate with said air intake to cause atmospheric air to be taken into said casing inadmixture with water flowing throughsaid aspirator and a float-controlled valve 'i-n said cpening for connection to the suetion side -'of-'the-pump controlled by a float in said casing; .whereby provided" the -water-level in the tank is above said normal water level, when the pump is started up, said float-controlled valve being at that time open, a flow-of water under pressure through said aspirator draws atmospheric air through said intake for introduction into the casing for subsequent displacement; therefrom into the tank through the valve-controlled connection to the tank.

2. In a hydro-pneumatic system including a hydro-pneumatic tank and pump for supplying water to the tank, an air charger for supplying air to the tank in accordance with the level of water therein as maintained by the pump, said charger comprising a casing for valve-controlled connection to the tank at about the normal water level therein, the connection permitting air flow therethrough in either direction and water flow only in the direction of the tank, said casing having a fluid flow opening for connection to the suction side of the pump, a valve-controlled air intake for admitting atmospheric air into said casing, an aspirator for connection to water under pressure from said pump and having a constricted throat portion vented directly to said valve for cooperation therewith to cause atmospheric air to be drawn into said aspirator upon water flow through said aspirator for introduction into the casing, and a float-controlled valve in that opening for connection to the suction side of the pump controlled by a float in said casmg.

3. In a hydro-pneumatic system including a hydro-pneumatic tank and a pump for supplying water to the tank through a discharge line, an

air charger for supplying air to the tank in accordance with the level of water therein as maintained by the pump, said charger comprising a casing having a first opening for valve-controlled connection to the tank at about the normal water level therein, the valve-controlled connection permitting air flow therethrough in either direction and water flow only in the direction of the tank, said casing having a second fluid flow opening for connectioon to the pump intake, a valvecontrolled air intake for admitting atmospheric air into the casing, an aspirator for connection to the discharge line of the pump and having a constricted throat portion vented to cooperate with said air intake to cause atmospheric air to be admixed with water flowing through the aspirator for subsequent introduction into the casing, a float-controlled valve in said second fluid flow opening and a float in said casing controlling said float-controlled valve, said casing being above the pump intake to provide a source of priming water for the pump.

4. In a hydro-pneumatic system including a hydro-pneumatic tank and a pump for supply ing water to the tank through a discharge line, an air charger for supplying air to the tank in accordance with the water level therein as maintained by the pump, said charger, comprising a casing having a first fluid flow opening for valvecontrolled connection to the tank at about the normal water level therein permitting air flow .therethrough in either direction and water flow only in the direction of the tank, said casing having a second fluid flow opening for connection to the intake side of the pump, a valve-controlled air intake, an aspirator for connection to the discharge line of the pump and discharging into said casing, said aspirator having its low pressure .throat zone vented in direct fluid flow communication with said air intake, and a float controlled valve in said econd fluid flow opening with its float in saidcasing. whereby fluid flow through said aspirator will draw air through said air intake for admixture with fluid flowing through the aspirator for separation within said casing and subsequent introduction into said tank through said first flow opening.

5. In a hydro-pneumatic system including a hydro-pneumatic tank, a pump for supplying water thereto, and a water supply pipe to said pump having a foot valve therein, an air charger having a first fluid flow opening for connection to the tank at about the normal water level therein and a second fluid flow opening for connection to the intake side of the pump, a check valve controlling the connection from said first fluid flow opening to permit air flow in either direction but preventing water flow from said tank to said charger, a float controlled valve in said second fluid flow opening, said charger having a third fluid fiow opening for connection to the discharge line of the pump, an air intake communicating with said third fluid flow opening, and an aspirator also communicating with said third fluid new opening and vented at its throat in direct communication with said air intake to draw air into said aspirator from said air intake and to discharge air in admixture with water into said air charger upon the flow of water under pressure therethrough.

6. In a hydro-pneumatic system including a hydro-pneumatic tank, a centrifugal pump for supplying water thereto through a discharge line, and a water supply pipe in said pump having a foot valve therein, an air charger providing a float chamber having a first fluid flow opening for connection to the tank at about the normal level of water therein, a second fluid flow opening for connection to the intake side of the pump for connection to the water supply pipe, and a third fluid flow opening for connection to the discharge line of the pump, means controlling fluid flow through said first flow opening to allow air flow in either direction and water flow only from said float chamber to the tank, a float controlled valve in said chamber for controlling said second fluid flow opening, an aspirator in said third fluid flow opening for receiving water from the pump discharge line and having a vented constricted throat, an air intake in direct communication at said vented aspirator throat so that water flow through the aspirator draws air into said aspirator from said air intake for introduction into said float chamber in admixture with water from said aspirator and a float in said chamber for controlling said float-controlled valve to close said valve when said float chamber is substantially filled with air and thus preventing air from being drawn into the pump.

'7. In a hydro-pneumatic system as described, the combination with a water pump having an intake and discharge of a float chamber mounted above said pump intake and in float valve-controlled communication therewith, a float in said chamber actuating said float valve, an aspirator having a vented constricted throat, said aspirator being connected to the discharge of said pump and to said float chamber and an air intake connected to said aspirator through said vented throat adapted to open when said pump is forcing water under pressure through said aspirator to permit air to be drawn into said water for discharge in admixture therewith into said float chamber.

8. In a hydro-pneumatic system including a hydro-pneumatic tank and a pump for supply ing water to the tank, an air charger comprising a float chamber having a flow opening for connection to the inlet of the pump, a float valve in said chamber for controlling said flow opening, a float in said chamber for actuating said float valve, Said chamber having a second fluid flow opening for connection to said tank, an aspirator having a vented constricted throat, said aspirator being adapted for the pressure flow of water therethrough from said pump and in flow communication with said float chamber, and an air intake connected to the vented throat or said aspirator and adapted to open when water flow through said aspirator is established to introduce a mixture of air and water into said chamber, said air and water mixture being separated in said chamber with the air being later introduced into said tank through said second flow opening when the pressure of the air within the chamber is suflicient to overcome pressure within said tank.

9. In a hydro-pneumatic system including a hydro-pneumatic tank and a pump for supplying water thereto, an air charger comprising a float chamber having a first fluid flow opening for connection to the intake side of said pump and a. second fluid flow opening for connection to the tank at about the normal water level therein, a float valve in said chamber for controlling said first fluid flow opening, a float in said chamber actuating said float valve, an aspirator having an intake side for fluid fiow connection with said tank and a discharge side for fluid flow connection with said chamber, said aspirator having a vented constricted throat, and an air intake connected to the vented throat of said aspirator and adapted to open upon water flow through the 5 troduction 0f the separated air into said tank through said second fluid flow opening.

10. In a hydro-pneumatic system including a hydro-pneumatic tank and a pump for supplying water thereto, an air charger comprising a casing 10 having a first fluid flow opening for connection to the intake side of a pump and a second fluid flow opening for connection to the tank at about the normal water level therein, a float in said casing, a valve actuated by said float for con- 15 trolling the flow of water through said first fluid flow opening, an aspirator having an intake 1'01 connection to the tank and an outlet for connection to the casing, said aspirator having a vented constricted throat, and an air intake connected 0 to the vented throat of the aspirator and adapted to open when water flow through the aspirator is established to introduce a mixture of air and water to said casing, said air and water mixture being gravity separated in said casing for subsequent introduction of the separated air into said tank through said second fluid flow opening.

ARTHUR W. BURKS.

REFERENCES CITED 30 The following references are of record in the flle of this patent:

UNITED STATES PATENTS 

